The Animal Resource and Clinical Core, together with its main component, the Animal Records Review Committee (ARRC), is that part of the Program Project which is responsible for all aspects of animal selection, health and suitability for our study of normal aging. These responsibilities breakdown into four separate functions. (1) The core will screen the Yerkes rhesus population in order to select and purchase animals for inclusion in the Program based upon a review the Yerkes Animal Records system to identify those animals which meet the health and history selection criteria developed jointly by staff members of the NIA and the Program Project. (2) Once selected the core will monitor the subjects throughout the conduct of the project to ensure their continuing suitability by regularly reviewing the health status of all monkeys in the Program. The Core will be responsible for the decision to terminate an animal promptly should medical or health conditions warrant as well as the decision to exclude its data from the study if there is a potential for confounding the study of normal aging. (3) The core will also review the results of the MRI scans and postmortem autopsies and pathological surveys to determine whether occult problems existed whose nature would warrant exclusion from the data analysis. (4) The core will also ensure prompt, thorough, and efficient access of all of the Projects to data on the current status of all monkeys enrolled in the Program and will disseminate the decisions of the Core on subject suitability. In addition to these major responsibilities this core will also coordinate the acquisition and hence assignment of animals to behavioral testing and will coordinate schedule of MRI scans and physical examinations so that all the projects obtain the required subjects as outlined in the Program timetable.